Mantled howling monkeys (Alouatta palliata) are New World Monkeys living in the Neotropics whose diet is primarily composed of foliage. In howlers, the primary sites of microbial fermentation are in the cecum and colon where a diverse group of microbes with cellulose-digesting abilities dwell. This digestive specialization is known as hindgut fermentation.

Commensal microbial communities play a key role in animal and human health, and the characterization of these populations is essential to understand divergent adaptations in closely related species. The emerging field of metagenomics combined with high throughput sequencing allows direct, unbiased interrogation of microbial populations, thus enabling the investigation of unique dietary differences in human and non-human primate species that may reveal the role of microbial communities in primate speciation.Here we present the first study of the structure of the intestinal bacterial community of the mantled howling monkey, using high-throughput sequencing and metagenomic analysis.

Our study showed that the fecal microbiome of the mantled howler was dominated by phyla Firmicutes (59.01%) with Bacteroidetes (13.81%), Unclassified (17.49%) and TM7 (3.61%) in lower concentrations. Compared to other non-human primate species examined in previous studies, the phylum TM7 comprised a much higher percentage of the fecal microbiome in mantled howling monkeys. This factor makes mantled howlers unique among other non-human primates previously studied in regards to their gut microbial community structure.

This study was funded by the University of Minnesota College of Veterinary Medicine.